Help on BLE Notify

[frax84]

Hello,
i'm working on "gatt_server" example using ESP32 as BLE server and Android app "BLEscanner" as BLE client. I have been able to make the basic code work so i can discovery and connect. I'm making experiments to improve my ESP-IDF knowledge (i'm using the esp-idf 2.0 RC) adding some features to the example but i'm having hard time with notifications. Let me explain with code:

I started declaring a variable:

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uint8_t experiment = 0xEE;

I use this variable as a check for the code for reading operation i use, the following one:

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case ESP_GATTS_READ_EVT: {
		esp_gatt_rsp_t rsp;
		memset(&rsp, 0, sizeof(esp_gatt_rsp_t));
		rsp.attr_value.handle = param->read.handle;
		rsp.attr_value.len = 1;
		rsp.attr_value.value[0] = experiment;
		esp_ble_gatts_send_response(gatts_if, param->read.conn_id,
				param->read.trans_id, ESP_GATT_OK, &rsp);
		break;

With this when i click on "READ" on a characteristic on the app i read the value 0xEE.
About the write operation i tried write this code:

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case ESP_GATTS_WRITE_EVT: {
		if (param->write.handle== gl_profile_tab[0].char_handle) {      //[0] because i'm using profile A
			experiment = (uint8_t)*param->write.value;
		} else if (param->write.handle== gl_profile_tab[0].descr_handle) {
			esp_ble_gatts_set_attr_value(gl_profile_tab[0].descr_handle, param->write.len,(uint8_t*) param->write.value);
			experiment=0xBB;
		}
		esp_ble_gatts_send_response(gatts_if, param->write.conn_id,param->write.trans_id, ESP_GATT_OK, NULL);
	break;

With this code i (TRY) to use the "write.handle" to filter the request. If i write the characteristic the program run the first if and the following READ reads the new "experiment" value. But if i click on NOTIFY experiment value doesn't change to "0xBB".

What i'm doing wrong? Any suggestion would be appreciated!

Regards,
Frax

[frax84]

Don't leave me alone! It's cold outside!

[MarkIngle]

This looks similar to what I am trying to learn. I am going work on understanding your code so that we can understand this together. Thanks for posting this!

[frax84]

Glad if my work fan help you. Let me know if you fine out something.

Frax

[AnthonyPhan]

I am also working on a similar problem. I will post here if I make any progress.

[kolban]

Can you describe in more detail the nature of your puzzle/problem?